JP2007522681A - Substrate support system for reducing autodoping and backside deposition - Google Patents

Abstract

  The substrate support system (140, 200, 300) comprises a relatively thin and circular substrate holder (100), which has a plurality of passages (116, 118, 120, 240) extending between its top and bottom surfaces. 340). The substrate holder (100) includes a single substrate support shelf or a plurality of substrate support spacer blades (124), and the blades (124) support the peripheral portion of the substrate back surface (154). As a result, a narrow gap (152) is formed between the substrate (16) and the substrate holder (100). The vanes (124) can be angled so that the reaction gas does not accumulate on the backside as the substrate holder (100) rotates. The hollow support members (22, 204, 304) can support the back surface (106) of the substrate holder (100). The hollow support member (22, 204, 304) allows a gas (eg, an inert gas or a cleaning gas) to pass up into one or more of the plurality of passages (116, 240) of the substrate holder (100). Formed to transport to. The gas transported upward flows into the gap (152) between the substrate (16) and the substrate holder (100). According to an embodiment of the present invention, the gas in the gap (152) is then either outward or upward around the edge (17) of the substrate or, if present, in the hollow support member (22, 204, 304). It flows downward through the passages (118, 120, 340) of the substrate holder (100) that do not lead to. The gas flowing outward and upward around the substrate edge (17) prevents the reaction gas above the substrate (16) from depositing on the back surface. Gases that do not communicate with the support member (22, 204, 304) and flow downward through the passages (118, 120, 340) push out-diffusing dopant atoms away from the surface (155) of the substrate, It is preferable to prevent autodoping. In one embodiment, the support member includes a support spider (22) with a multiplicity of hollow arms that transport gas into a passage selected from the plurality of passages (116). In other embodiments, the support member includes a bowl-shaped or cup-shaped structure (204) that transports gas upward into the entire passageway (240). In still other embodiments, the support member includes a bowl-shaped or cup-shaped structure (304) that is in all of the plurality of passages (240), however, one or more. Transport gas upward into the passage.

Description

Priority Claims This application is a provisional patent application 60 / 545,181 to Goodman et al. Filed on February 13, 2004 and a provisional patent application 60 / 591,258 to Stoutyesdijk et al. Filed July 26, 2004. Claiming priority under 35 USC 119 (e).
INCORPORATION BY REFERENCE This application is hereby incorporated by reference into US Pat. No. 6,093,252, non-provisional patent application No. 10 / 697,401 to Keeton et al. The provisional patent application 60 / 545,181 to Goodman et al. And the provisional patent application 60 / 591,258 to Stoutyesdijk et al. Incorporate

  The present invention relates generally to semiconductor processing equipment, and more particularly to systems and methods for supporting a substrate during a material deposition process.

  For various reasons, high temperature furnaces or reactors are used to process substrates. In the electronics industry, integrated circuits are fabricated by processing substrates such as semiconductor wafers. A substrate, generally a circular silicon wafer, is placed on the substrate holder. If the substrate holder facilitates attracting radiant heat, the substrate holder is called a susceptor. The substrate and the substrate holder are enclosed in a reaction chamber, are generally made of quartz, and are heated to a high temperature by a plurality of radiant heating lamps arranged around the quartz chamber. In an exemplary high temperature process, a reactive gas passes over the substrate to be heated, and a thin layer from the reactant material undergoes chemical vapor deposition (CVD) on the substrate surface. As used herein, the terms “processing gas”, “processing gas”, and “reactive gas” generally refer to a gas containing a material to be deposited on a substrate (such as a silicon-containing gas). As used herein, these terms do not include cleaning gases. Subsequent processes produce a layer of reactant material that is deposited on the substrate in the integrated circuit. The flow of process gas over the substrate is often controlled to promote deposition uniformity on or on the substrate. Deposition uniformity can be further facilitated by rotating the substrate holder and wafer about a vertical central axis during deposition. As used herein, the “front surface” of the substrate refers to the top surface of the substrate, and the “back surface” of the substrate refers to the bottom surface of the substrate.

As described above, a general substrate to be processed includes a thin silicon layer. In the manufacture of integrated circuits, it may be desirable to deposit additional silicon (eg, by CVD) on the substrate surface. When new silicon is deposited directly on the silicon surface of the substrate, the newly deposited silicon maintains the crystal structure of the substrate. This is known as epitaxial deposition. However, the surface of the original substrate to be processed is generally polished and naturally covered with a natural oxide layer (for example, SiO ₂ ). Depositing new silicon on the native oxide layer is known as polysilicon deposition. In order to perform epitaxial deposition, it is usually necessary to remove the native oxide layer from each side (ie, the top and / or bottom surface of the substrate) where new silicon will be deposited. The native oxide layer is typically removed by exposure to a cleaning gas such as hydrogen gas (H ₂ ) before depositing new silicon. As used herein, the term “cleaning gas”, unlike reactive gas, does not include reactive gas.

  There are a wide variety of different types of substrate holders for supporting a substrate during processing. A typical substrate holder includes a body having a generally horizontal top surface under a supported substrate. The spacer means is often provided in order to maintain a narrow gap between the supported substrate and the horizontal upper surface. This gap prevents the processing gas from sticking to the substrate holder. The substrate holder often includes an annular shoulder that surrounds the supported substrate. One type of spacer means includes a spacer element secured to the substrate holder body, such as an annular lip, a plurality of small spacer lips, spacer pins or knots. Another type of spacer element includes a plurality of vertically movable lift pins that are adjusted to pass through the substrate holder body and support the substrate above the top surface of the substrate holder. As is often the case, the spacer elements are arranged to contact the substrate only within the “exclusion zone”, which is the radially outermost portion of the substrate, where: It is difficult to maintain deposition uniformity. Exclusion zones are not typically used in the development of commercial integrated circuits. For example, the substrate to be processed may be regarded as having an exclusion zone of 5 mm from the edge.

  One problem associated with CVD is the phenomenon of “backside deposition”. Many substrate holders are not sealed around the substrate, so that process gas may flow from around the peripheral edge of the substrate into the gap between the substrate and the substrate holder. These gases tend to deposit on the back side of the substrate as small bumps at or near the edge of the substrate and as an annular ring. This makes the substrate thickness non-uniform, which is generally detected by a nanotopology tool. Such non-uniform substrate thickness adversely affects the next processing step such as photolithography, and in many cases makes the next processing step impossible.

Prior to epitaxial deposition, the surface of the substrate is typically exposed to a cleaning gas to remove the native oxide layer. However, around the substrate that is not sealed, the cleaning gas contacts the back surface of the substrate, and as a result, the oxide on the back surface is removed. The amount of cleaning gas in contact with the backside of the substrate is usually not sufficient to remove the entire oxide layer. However, the cleaning gas tends to open a pinhole-type opening in the oxide layer on the back surface of the substrate and expose the silicon surface. In particular, pinhole-type openings tend to be annular rings or “halos”. Of course, the longer exposed to the cleaning gas, the more the cleaning gas flows inward toward the center of the substrate, and more pinhole-type openings are created in the oxide layer. Some of the removed oxide is redeposited on the oxide layer on the backside of the substrate and the SiO ₂ aggregates to form ridges. Once deposition begins, process gas may flow out of the substrate above and around the edge of the substrate as well. Partial removal of native oxide can result in process gas material being mixed and deposited on the backside of the substrate, epitaxially deposited on the exposed silicon surface, and polysilicon deposited on the oxide layer. There is sex. Since the agglomerated SiO ₂ can receive unused process gas, the intensity of the halo is sometimes high. This can result in reduced polysilicon growth or bumps. These polysilicon bumps scatter light and thicken the haze. Thus, one way in which backside deposition can be detected is to perform epitaxial deposition and then visually inspect the backside of the substrate for halo or haze.

  One method of reducing backside deposition involves the use of a purge gas that flows upward around the edge of the wafer to reduce the downward flow of cleaning or processing gas. For example, US Pat. No. 6,113,702 to Halpin et al. Discloses a two-part susceptor supported by a hollow gas transport spider. The two parts of the susceptor form a gas flow path between them. During deposition, an inert purge gas is transported up into the flow path formed in the susceptor through the spider, and the purge gas moves up around the edge of the substrate so as not to flow process gas on the backside of the substrate. To flow.

  Another problem in semiconductor processing is known as “autodoping”. The formation of an integrated circuit requires the deposition of a dopant material (such as doped silicon) on the surface of the substrate. Autodoping involves dopant atoms diffusing downward in the substrate, exiting from the back side of the substrate, and then flowing up around the edge of the substrate between the substrate and the substrate holder, generally near the edge of the substrate The tendency to redeposit on the substrate surface. Such redeposited dopant atoms can adversely affect the characteristics of the integrated circuit, particularly the semiconductor die near the edge of the substrate. Autodoping is more likely to occur and become more problematic as more substrate is doped.

  One way to reduce autodoping is to provide a plurality of holes in the susceptor so that gas can flow between the upper and lower regions of the susceptor. Autodoping is reduced by directing the gas flow horizontally just below the susceptor. Some of the gas flows upward from the holes in the susceptor and into the gap area between the susceptor and the substrate supported thereon. As the diffusing dopant atoms emerge from the backside of the substrate, they are forced down by the gas through the holes in the susceptor. Thus, the dopant atoms are likely to be swept into the region under the susceptor due to the venturi effect. Exemplary references disclosing conventional substrate holders using this method are in US Pat. No. 6,444,027 to Yang et al. And US Pat. No. 6,596,095 to Ries et al. is there.

  There are some limitations to conventional substrate support methods and systems to prevent backside deposition and autodoping. A typical purge gas system typically includes a gas flow channel for flowing purge gas through the substrate holder. These channels often impinge relatively concentrated and high-speed purge gas directly against the backside of the substrate. This can cause local cooling or “cold spots” on the substrate, which adversely affects the uniformity of the material deposited on the substrate. Furthermore, typical purge gas systems are generally not designed to prevent autodoping.

  Conversely, conventional systems that prevent autodoping are typically not designed to prevent backside deposition of reactant gases. For example, the systems disclosed in both US Pat. No. 6,444,027 to Yang et al. And US Pat. No. 6,596,095 to Ries et al. It is necessary to push the dopant atoms that diffuse out by flowing a gas from the back surface of the supported substrate through the flow path of the substrate holder. In addition, these systems generally require a complete or near fluid tight separation between the upper and lower regions of the substrate holder, the purpose of which is to allow the reaction gas to flow under and above the substrate holder. It is to prevent it from flowing to the back surface of the substrate through the flow path of the holder. Unfortunately, it is often very difficult to achieve a completely fluid tight separation between the upper and lower regions of the substrate holder. A divider plate is generally provided, but is usually provided with some clearance, especially if the substrate holder is designed to rotate during processing. Therefore, there is a considerable risk that the reaction gas accumulates on the back surface of the substrate.

  Accordingly, it is a primary object and advantage of the present invention to overcome some or all of these limitations and provide an improved design for a substrate support system. Another object and advantage of the present invention is to provide a simple and versatile substrate holder that helps reduce backside deposition and autodoping. Another object and advantage of the present invention is to provide a system and method that prevents backside deposition and autodoping by forcing a gas stream. Another object and advantage of the present invention is to provide a hollow support member that supports the underside of the substrate holder and transports gas flowing upward into the flow path of the substrate holder. Another object and advantage of the present invention is that through this hollow support member there is a risk that the gas transported upward will move somewhat slowly and indirectly to the backside of the substrate, thereby locally cooling the substrate. It is forming so that it may become low. Other objects and advantages of the present invention will be understood from the following description.

  In one aspect, the present invention provides a substrate support system comprising a substrate holder for supporting a substrate. The substrate holder includes a central portion, at least one spacer extending upward from the central portion, and a hollow support member. The central portion has an upper surface, a lower surface, and a plurality of open passages extending from the upper surface to the lower surface. The at least one spacer has an upper support surface that is raised upward from the upper surface of the central portion. The upper support surface of the at least one spacer is formed to support the peripheral portion of the substrate such that a gap region exists between the upper surface of the central portion and the bottom surface of the substrate. The hollow support member has an inlet that is adapted to engage the outlet of the gas transporter to facilitate the flow of gas from the gas transporter to the hollow support member. The hollow support member also has one or more open upper ends that are adapted to support the lower surface of the central portion of the substrate holder. One or more open upper ends are formed to transport gas upward into the lower ends of one or more of the plurality of passages in the central portion of the substrate holder. At least one of the plurality of passages has a lower end portion opened to a region outside the hollow support member.

  In another aspect, the present invention provides a substrate support system comprising a substrate holder for holding a substrate and a hollow support spider. The substrate holder includes a central portion and a plurality of spacers extending upward therefrom. The central portion has an upper surface, a lower surface, and a plurality of passages extending from the upper surface to the lower surface. The spacer has a raised upper support surface above the upper surface of the central portion. The upper support surface of the spacer is formed so as to support the periphery of the substrate such that a gap region exists between the upper surface of the central portion and the bottom surface of the substrate. The support spider includes a hollow manifold and a plurality of hollow arms extending generally radially outward and upward therefrom. The manifold has an inlet that is adapted to engage the outlet of the gas transport to facilitate the flow of gas from the gas transport into the manifold. The hollow arm is formed to receive a gas flow from the manifold. The hollow arm has an open upper end adapted to support the lower surface of the central portion of the substrate holder. The open upper end of the hollow arm is formed to transport gas upward into a subset of the passages in the center of the substrate holder.

  In another aspect, the present invention provides a substrate support system comprising a substrate holder for supporting a substrate and a hollow support member. The substrate holder includes a generally flat central portion and a plurality of spacers extending upward therefrom. The central portion has an upper surface, a lower surface, and a plurality of open passages extending from the upper surface to the lower surface. The spacer has a raised upper support surface above the upper surface of the central portion. The upper support surface of the spacer is formed so as to support the periphery of the substrate such that a gap region exists between the upper surface of the central portion and the bottom surface of the substrate. The hollow support member includes a lower base member and an annular wall extending upward therefrom. The base member has an inlet that is adapted to engage the outlet of the gas transport to facilitate the flow of gas from the gas transport into the hollow support member. The annular wall has an upper edge that allows gas in the annular wall and between the base member and the bottom surface of the substrate holder to pass between the upper edge of the annular wall and the bottom surface of the substrate holder. The support is formed on the bottom surface of the substrate holder so as to be substantially prevented from flowing through the substrate holder. The upper edge of the annular wall defines the upper opening of the hollow support member. The upper opening is formed in the lower end so as to transport gas upward into at least 10 of the plurality of passages in the central portion of the substrate holder.

  In another aspect, the present invention provides a substrate holder for holding a substrate, the substrate holder including a central portion and a plurality of spacers extending upward therefrom. The central portion includes a first set of an upper surface, a lower surface, and a plurality of open passages extending from the upper surface to the lower surface, and a plurality of open passages extending from the upper surface to one of the plurality of recesses in the lower surface. And a second set. Each recess is adapted to receive one upper end of a corresponding plurality of upper ends of the tubular arm of the hollow support member, the upper end supporting a central portion and a second gas comprising a plurality of passages. It is configured to be transported upward into the set. The spacer has a raised upper support surface above the upper surface of the central portion. The upper support surface of the spacer is formed so as to support the periphery of the substrate such that a gap region exists between the upper surface of the central portion and the bottom surface of the substrate.

  In yet another aspect, the present invention provides a hollow support member for supporting a substrate holder. The substrate holder is formed to support the substrate during substrate processing. The hollow support member includes a base member and an annular wall extending upwardly therefrom. The base member has a lower inlet that is adapted to engage the upper end of the hollow tube to facilitate gas flow upward from the tube into the hollow support member. The annular wall has an upper edge that allows gas in the annular wall and between the base member and the bottom surface of the substrate holder to pass between the upper edge of the annular wall and the bottom surface of the substrate holder. The support is formed on the bottom surface of the substrate holder so as to be substantially prevented from flowing through the substrate holder. The upper edge defines the upper opening of the hollow support member. The top opening defines an area that is at least 70% of the size of the substrate designed to be specifically supported by the substrate holder.

  In yet another aspect, the present invention provides a method for processing a substrate. This method requires a substrate holder having a generally flat central portion and a plurality of spacers extending upward therefrom. The central portion has an upper surface, a lower surface, and a plurality of open passages extending from the upper surface to the lower surface. The spacer has a raised upper support surface above the upper surface of the central portion. The upper support surface of the spacer is formed so as to support the periphery of the substrate such that a gap region exists between the upper surface of the central portion and the bottom surface of the substrate. According to this method, a substrate holder is provided, and then the substrate is placed thereon such that the upper support surface of the spacer supports the peripheral edge of the substrate. The upward flow of gas is directed directly into the lower end of one or more selected passages of the plurality of passages such that the gas flows into the gap region. The lower end of the remaining one or more passages of the substrate holder remains open.

  In yet another aspect, the present invention provides a substrate processing method. This method requires a substrate holder having a generally flat central portion and a plurality of spacers extending upward therefrom. The central portion has an upper surface, a lower surface, and a plurality of open passages extending from the upper surface to the lower surface. The spacer has a raised upper support surface above the upper surface of the central portion. The upper support surface of the spacer is formed so as to support the periphery of the substrate such that a gap region exists between the upper surface of the central portion and the bottom surface of the substrate. According to this method, a substrate holder is provided, and then the substrate is placed thereon such that the upper support surface of the spacer supports the peripheral edge of the substrate. Next, a hollow support member is provided, and the hollow support member has a base and an annular wall extending upward from the base. The annular wall has an upper edge that is formed to engage the bottom surface of the substrate holder. The annular wall is engaged with the bottom surface of the substrate holder such that some of the passages have a lower end arranged to direct the downwardly flowing gas into the hollow support member, and At least one of the passages has a lower end arranged to direct the gas flowing downward into the region outside the hollow support member. The gas flow is then directed directly into the inlet of the hollow support member.

  In order to summarize the present invention and its advantages over the prior art, certain objects and advantages of the present invention have been described above. Of course, it is to be understood that not all such objects or advantages may be obtained by any particular embodiment of the present invention. Thus, for example, to achieve or optimize one advantage or group of advantages as taught herein, without necessarily achieving other objects or advantages as taught or suggested herein. In addition, those skilled in the art will appreciate that the present invention may be practiced or carried out.

  All of these embodiments are intended to be within the scope of the invention disclosed herein. These and other embodiments of the present invention will be readily apparent to those skilled in the art from the following detailed description of the preferred embodiment with reference to the accompanying drawings. The invention is not limited to any particular preferred embodiment disclosed herein.

  In some cases, the drawings are not drawn to scale.

  Before describing the substrate holder of the present invention, an exemplary CVD reactor is disclosed. An exemplary CVD reactor 10 including a quartz reaction chamber 12 is shown in FIG. A radiant heating element 14 is supported outside the transparent chamber 12 and supplies thermal energy to the chamber 12 without being measurablely absorbed by the chamber walls. Although the preferred embodiment is described with reference to a “cold wall” CVD reactor, it will be understood that the substrate support system described herein may be used for other types of reactors and semiconductor processing equipment. Those skilled in the art will appreciate that the claimed invention is not limited to use within the specific reactor 10 disclosed herein. In particular, those skilled in the art will appreciate the applications for the substrate support system described herein for other semiconductor processing equipment. In this application, the substrate is supported while being uniformly heated or cooled. Further, although shown in connection with a typical silicon wafer, the support described herein may be used to support other types of substrates, such as glass, these substrates are CVD, It undergoes processes such as physical vapor deposition (PVD), etching, annealing, dopant diffusion, and photolithography. A support is a specific facility for supporting a substrate during a processing process at a high temperature. Further, those skilled in the art will appreciate that the present invention includes a substrate holder that is a susceptor and a substrate holder that is not a susceptor. An exemplary alternative reaction chamber suitable for the substrate support system of the present invention is described in US Pat. No. 6,093,252.

  The radiant heating element 14 generally includes two banks of long tube type heating lamps, which are arranged in a direction perpendicular to or crossing the substrate holder that holds the semiconductor substrate. Each top and bottom surface of the substrate faces one of the two banks of heating lamps 14. A controller in the thermal reactor adjusts the power to each lamp 14 to maintain a desired temperature during wafer processing. Some spot lamps are used to compensate for the heat sink effect of the lower support structure.

  The substrate shown here includes a semiconductor wafer 16 having a generally circular edge 17 as shown in FIG. The support system 140 shown here includes a substrate holder 100 on which the wafer 16 is placed, and a hollow support spider 22 that supports the holder 100. One embodiment of the substrate holder 100 is shown in more detail in FIGS. The substrate support system 140 is shown in more detail in FIGS. The spider 22 is preferably made of a non-metallic material that is transparent (to reduce contamination). The spider 22 is attached to a gas transporter 144 (eg, a tube or shaft) that extends downwardly through a tube 26 that hangs from the lower wall of the reaction chamber 12. The spider 22 has at least three hollow substrate holder supports or arms 148 that extend upwardly from the shaft 24 radially outward. The arms 25 are preferably separated at the same angle around the vertical central axis of the shaft 24, and the shaft 24 is preferably aligned with the vertical central axis of the substrate holder 100 and the wafer 16. For example, when there are three arms 148, it is preferable that they are separated from each other by 120 °. As will be described later, the arm 148 is formed to support the bottom surface of the substrate support holder 100. In a preferred embodiment, the substrate holder 100 includes a susceptor that absorbs radiant energy from the heating element 14 and re-radiates such energy. The substrate holder 100 is preferably solid and made of one component. The gas transporter 144, spider 22, and holder 100 are preferably formed to rotate simultaneously about a vertical axis during substrate processing.

  A central temperature sensor or thermocouple 28 for detecting the central temperature of the substrate holder 100 may be provided. In the illustrated embodiment, the temperature sensor 28 extends through the gas transporter 144 and the spider 22 near the substrate holder 100. Additional peripheral temperature sensors or thermocouples 30 that are housed in slip rings or temperature compensation rings 32 are also known, which surround the substrate holder 100 and the wafer 16. The thermocouples 28, 30 are connected to a temperature controller (not shown) that controls and sets the power of the various radiant heating elements 14 in response to the readings of the thermocouples 28, 30. To do.

  In addition to housing the thermocouple 30, the slip ring 32 also absorbs radiant heat during high temperature processing. The heated slip ring 32 helps reduce the heat loss of the wafer edge 17. The slip ring 32 can be suspended by a variety of suitable means. For example, the slip ring 32 shown here rests on an elbow-shaped portion 34 that hangs from a quartz reaction chamber partition 36. A partition 36 divides the reactor 10 into an upper chamber 2 and a lower chamber 4 that are designed to flow reactants or process gases (eg, for CVD to the substrate surface). The partition 36 and other elements of the reactor 10 preferably substantially prevent fluid communication between the chamber 2 and the chamber 4. However, since the substrate holder 100 is preferably capable of rotating about a vertical central axis, there is generally a narrow gap between the holder 100 and the slip ring 32 (or other element). Therefore, it is often difficult to completely prevent fluid communication between the chamber 2 and the chamber 4.

  2 and 3 are a perspective view, as seen from above, and a perspective view, as seen from the bottom, of one embodiment of the substrate holder 100, respectively. The holder 100 shown here is formed as a single component and is generally circular and disc-shaped. It includes a central portion 102 having an upper surface 104 and a lower surface 106. The top surface 104 can be generally flat or planar, or alternatively concave. The upper surface of the holder 100 includes a plurality of spacers having an upper surface formed to support the semiconductor substrate 16 (FIG. 1). In the illustrated embodiment, such a spacer includes a ring 110 (FIGS. 5 and 6) consisting of spacer vanes 124 that surround or circle around the top surface 104 of the central portion 102. As will be described later, the spacer blade 124 has an upper surface formed so as to support the peripheral edge of the back surface of the semiconductor substrate 16 (FIG. 1). The spacer blades 124 are preferably polished to prevent or minimize scratches on the back surface of the substrate 16. The vanes 124 preferably contact the substrate 16 only in the exclusion zone. By using the blades for a rigid substrate support shelf, heat transfer from the substrate holder to the backside of the substrate 16 (at the substrate edge 17) is minimized. This reduces the temperature non-uniformity of the substrate 16 (due to the temperature difference between the substrate and the substrate holder 100), thus improving the slip characteristics. However, the ring 110 of the vane 124 may be replaced with a rigid support shelf. A raised annular shoulder 108 surrounds the ring 110 of the vane 124. The shoulder 108 defines a substrate pocket 112 that receives the substrate 16 supported by the spacer blades 124. In one embodiment, the substrate holder 100 is a susceptor that can absorb and re-radiate radiant energy. Such susceptors may be formed from graphite coated with silicon carbide, but those skilled in the art will appreciate that other materials may be suitable.

  Referring to FIG. 3, the lower surface 106 of the central portion 102 of the substrate holder 100 includes a plurality of recesses 114, each of which is an upper end of a support arm 148 of a support spider 22 with a plurality of hollow arms. It is preferably sized to receive the portion 150 and so formed (FIGS. 1, 8). The number of recesses 114 is preferably equal to the number of arms 148 of the spider 22. Each recess 114 is preferably sized to closely receive a corresponding support arm 148 to minimize gas leakage as described below. However, a clearance fit may be used if desired. The recesses 114 are preferably arranged at equal angular intervals around the center of the substrate holder 100. In the embodiment shown here, the three recesses 114 are arranged at an angle interval of 120 °. The placement of the recesses 114 is known to occur in some systems, so that the spider 22 can stably support the holder 100, however, the momentum force becomes too great and the spider arm 148 may bend. Is preferably located sufficiently far from the center of the substrate holder 100 in the radial direction.

The central portion 102 of the substrate holder 100 includes a plurality of passages or holes extending from the upper surface 104 to the lower surface 106. In the illustrated embodiment, the passages include a first set of twelve passages 116, a second set of eight passages 118 disposed radially inward of the first set of passages 116, and passages. And a third set of 39 passages 120 disposed radially outward from the first set of 116. As shown in FIG. 3, the lower end of the passage 116 is in the recess 114. In the embodiment shown here, each recess 114 includes the lower end of four of the passages 116. The passage 118 is arranged in a generally circular shape near or around the center of the substrate holder 100. The passage 120 is arranged in a radial direction between the ring 110 consisting of vanes and the three groups consisting of passages 116, generally in three identical central circles. It will be appreciated that the passageway of the central portion 102 can be in a wide variety of arrangements and that the arrangement shown here is merely an example. The number of passages 116, 118, and 120 is preferably within about 9-250, but within about 6-225, within about 20-250, within about 50-200, within about 100-200, or about 100. It may be within ~ 250. Lower surface 106 of the central portion 102, the density of passages 116, 118, and 120, is preferably a 1 cm ² per 0.01 to 3.0 passageway, 1 cm ² per 0.05 to 2.5 within passageway, It may be within 0.10 to 2.5 passages per 1 cm ^{2 and} within 0.20 to 2.5 passages per 1 cm ^{2 and} within 0.50 to 2.0 passages per 1 cm ² . As shown in FIG. 3, the holder 100 includes a central recess 122 adapted to receive a central temperature sensor or thermocouple 28 (FIG. 1).

  The first set of passages 116 is tilted or angled with respect to the vertical so that gas flowing upward in the passages 116 of one recess 114 is directed away from the center of the recesses 114. Is preferred. Some or all of the second set of passages 118 may be inclined so that the upper end (on the upper surface 104 of the central portion 102) is radially outward from the lower end (on the lower surface 106 of the central portion 102). preferable. Some or all of the third set of passages 120 are preferably inclined so that the upper end (at the upper surface 104) is radially inward from the lower end (at the lower surface 106 of the central portion 102). The passages 116, 118, and 120 are preferably inclined at an angle in the range of 30 ° -60 ° with respect to the vertical, and more preferably at an angle of about 45 ° with respect to the vertical. The diameter of the passage 116 is preferably in the range of 0.04 to 0.25 inches, and more preferably in the range of about 0.080 inches. The diameter of the passages 118 and 120 is preferably in the range of 0.04 to 0.25 inches, and more preferably in the range of about 0.100 inches. Considering the goal of allowing gas to flow into the passage, the passage may be of other diameters.

  The passages 116, 118, and 120 may be generally equally distributed in the central portion 102. In other embodiments, the passages may be randomly arranged in the central portion 102. The passages may be formed in any pattern suitable for supplying fluid into the central portion 102. It is contemplated that the passageway can be any size and shape suitable to make fluid flow to the substrate holder 100 desirable. The diameter and orientation of the passage can be determined based on, for example, the desired flow rate of gas passing through the central portion 102 and the desired angle at which the gas supplied by the passage strikes the back surface 154 of the substrate 16. Further, the passages may be similar or different from each other if desired.

  4 and 5 are a cross-sectional view and an enlarged plan view of the peripheral portion of the substrate holder 100 of FIGS. 2 and 3, and show the shape of the edge of the holder in more detail. As described above, the holder 100 includes an outer annular shoulder 108 outside the ring 110 of the spacer blade 124. The upper surface 132 of the shoulder 108 is raised above the vane 124 so that the shoulder 108 is supported on the vane 124 at the periphery 17 (FIGS. 1, 7, and 8) of the substrate 16. Surrounding is preferred. In a preferred embodiment, the spacer blades 124 are spaced apart from each other and generally parallel, with each blade 124 angled with respect to the center of the blade ring 110. In this context, “substantially parallel” means that the vanes 124 are oriented in substantially the same direction and, when curved, have a side-by-side curvature that matches to some extent. The blade 124 shown in FIG. 5 is somewhat curved so that the radially inner end is positioned closer to the radial direction than the radially outer end. A channel 126 is defined between the vanes 124. Referring to FIG. 5, when the holder 100 is rotated clockwise, the angled vanes 124 substantially prevent or prevent gas from flowing radially inward through the channel 126 and substantially. It will be appreciated that the gas helps to flow radially outward through the channel 126. When the holder 100 rotates counterclockwise, the opposite phenomenon is observed. Alternatively, those skilled in the art will appreciate that the spacer blades 124 may be straightened (as opposed to curving as shown in FIG. 5). FIG. 6 shows an alternative shape in which the blades 124 are straightened.

  In the embodiment shown in FIGS. 4 and 5, the ring 110 of the spacer blade 124 is surrounded by a shallow annular groove 128, which minimizes radiation loss from the substrate 16 (FIG. 1) to the substrate holder 100. To help. The holder 100 also includes an annular insulating groove 130 disposed radially inward from the bladed ring 110 and the shallow annular groove 128. In the region of the bladed ring 110 where the substrate 16 is supported by the holder 100 and is in thermal contact with the holder 100, the thermal insulation groove 130 helps to compensate for heat transfer from the substrate 16 to the holder 100. Details of the design and shape of spacer vanes 124, grooves 128, and grooves 130 are further described in US patent application Ser. No. 10 / 697,401.

  7 and 8 illustrate a substrate support system 140 that has the substrate holder 100 of FIGS. 2 and 3 supported by a hollow support spider 22. FIG. 7 is a plan view showing a state in which the substrate 16 is supported on the holder 100. In FIG. 7, the contour of the recess 114 is indicated by a dotted line. FIG. 8 is a cross-sectional view of the substrate support system 140 taken along line 7-7 of FIG. The support spider 22 includes a hollow body or manifold portion 146 that has a lower inlet 142 that passes gas from the gas transporter 144 into the manifold portion 146. Engage with the upper end or outlet 143 of the gas transporter 144 to facilitate the movement. The spider 22 is preferably fluidly engaged with the gas transporter 144. In this embodiment, the gas transporter 144 includes a rigid vertical tube. The gas transporter 144 preferably supports the spider 22. For example, the inlet 142 of the spider 22 can be configured to be tightly attached (eg, threadedly engaged) to the outlet 143 of the gas transporter 144. Alternatively, the manifold portion 146 may include an inner flange (not shown) that rests on the upper end of the gas transporter 144. Further, the manifold portion 146 can be sized to be inserted into the outlet 143 of the gas transporter 144. Those skilled in the art will appreciate that there are various configurations in which the gas transporter 144 will support the spider 22. Any of them can be used in any of the embodiments of the present invention.

  The spider 22 includes a plurality of hollow tubes or arms 148 that extend generally radially outward and upward from the manifold portion 146 such that the arm 148 receives a gas flow from the manifold portion 146. Is formed. It will be appreciated that the tube or arm 148 need not be cylindrical, but can have a variety of other cross-sectional shapes and sizes. Furthermore, the cross-sectional shape and size may vary along the length. The arm 148 has an open upper end 150 that supports the lower surface 106 of the central portion 102 of the substrate holder 100. In the illustrated embodiment, the upper end 150 is received in the recess 114 of the holder 100. The upper end 150 of the arm 148 is formed to transport gas upward into the passage 116 of the recess 114, preferably in a fluid tight manner. It will be appreciated that the number of passages 116 through which the spider 22 supplies gas can be varied as desired. In some implementations, it is only necessary to have one passage 116 that receives gas from the spider 22, in which case the spider need only include one hollow arm 148. Receiving the upper end 150 of the arm 148 into the recess 114 also helps to convey the rotation of the spider 22 to the rotation of the holder 100.

  As shown in FIG. 8, the peripheral edge of the substrate 16 is supported by the upper support surface (FIGS. 5 and 6) of the ring 110 of the spacer blade 124. The size of the spacer blade 124 is such that a thin gap region 152 exists between the upper surface 104 of the central portion 102 and the back surface 154 of the substrate 16. The height of the gap region 152 is adjusted by the height of the spacer blade 124. The gap region 152 is preferably substantially uniform in height. For simplicity of illustration, the arrangement and number of passages 116, 118, and 120 in FIG. 8 is somewhat different from the arrangement and number shown in FIGS. Those skilled in the art will appreciate that the arrangement and number of passages may vary widely.

  The substrate holder 100 and the support spider 22 may be formed from materials having similar or different coefficients of thermal expansion. In one embodiment, the holder 100 and the spider 22 have the same coefficient of thermal expansion to reduce relative movement between the lower surface 106 of the holder 100 and the upper end 150 of the support arm 48 of the spider 22.

  The use of the substrate support system 140 to process the substrate 16 will now be described. The substrate 16 is placed on the substrate holder 100 such that the upper support surface of the spacer blade 124 supports the peripheral edge of the substrate. A gas source is provided that injects an inert gas stream (also known as “purge gas” or “sweep gas”) upward into the gas transporter 144. In FIG. 8, the inert gas flow is indicated by arrows. The inert gas flows into the manifold portion 146 of the support spider 22 and then into the hollow arm 148. The inert gas continues to flow upward in the passage 116 and into the gap region 152. As shown here, the passage 116 is inclined so that the inert gas flow does not impinge on the substrate 116 at an angle of 90 °. This helps reduce the extent to which the inert gas flow can undesirably cool the substrate 16 and create cold spots in the substrate 16. Upon exiting the passage 116, the inert gas flows through the gap region 152. Some of the inert gas flows into the upper reactor chamber 2 radially outward through the channel 126 (FIG. 5) between the spacer blades 124 and upward around the peripheral edge 17 of the substrate 16. The remainder of the inert gas exits the gap region 152 by flowing downwardly into the lower reactor chamber 4 through the passages 118 and 120 of the holder 100. Optionally, a second flow of gas (preferably inert gas) is directed into the lower chamber 4 generally below and parallel to the lower surface 106 of the central portion 102 of the substrate holder 100 in the passages 118 and 120. The inert gas exiting from the lower end can be swept away. A separate downstream reactor outlet or exhaust for removing these mixed gas streams may be provided in the chamber 4 under the quartz chamber partition 36 (FIG. 1).

  As explained above, the second set of passages 118 and the third set of passages 120 are also tilted or angled with respect to the vertical. As shown in FIG. 8, the second set of passages 118 is inclined so that the lower end portion is radially inward of the upper end portion. This facilitates the flow of the inert gas from the passage 116 radially inward toward the passage 118, thereby facilitating the flow of the inert gas downward through the passage 118. The 3rd set which consists of a plurality of passages 120 inclines so that a lower end part may become the diameter direction outward of an upper end part. As a result, the inert gas also tends to flow radially outward from the passage 116 toward the passage 120, so that the inert gas is facilitated to flow downward in the passage 120. Thus, angling the passages 118 and 120 described herein facilitates the flow of inert gas downward from the gap region 152 into the lower reactor chamber 4. By angling the passages 118 and 120, the risk of the substrate back surface 154 being directly exposed to the radiant energy from the heating element 14 under the holder 100 is also reduced (FIG. 1). In order to further reduce this risk, the path of the substrate holder 100 may be a non-linear shape that prevents radiant energy from directly plugging into the substrate back surface 154. For example, each passage may comprise a vertical portion and an angled portion.

  Similar to the flow of the inert gas described above, the reaction processing gas is guided substantially horizontally above the substrate 16 in the upper reactor chamber 2. Due to the flow of the reaction gas, the processing material is deposited on the surface 155 of the substrate 16. By flowing the inert gas upward around the edge 17 of the substrate 16, it is substantially reduced, suppressed and prevented from flowing downwardly around the edge 17 of the substrate and into the gap region 152. . Thus, the inert gas substantially reduces, inhibits or prevents deposition of process gas on the backside of the substrate. In addition, the support spider 22, holder 100, and substrate 16 preferably rotate about a central vertical axis during processing. In general, the gas transport tube 144 is rotatable and transmits the rotation to the spider 22, the holder 100, and the substrate 16. As described above, the holder 100 preferably rotates in a direction in which the angled spacer blades 124 prevent the reaction gas from flowing radially inward in the channel 126 between the blades. The angled spacer vanes 124 also help the inert gas flow radially outward through the channel 126, which further reduces, inhibits or prevents the flow of process gas inside. Thus, the angled spacer blades 124 further reduce or prevent backside deposition further in the vicinity of the substrate edge 17. In this regard, the blade 124 was angled, resulting in a 10-fold improvement over the prior art substrate holder.

  It will be appreciated that the substrate support system 140 reduces or prevents autodoping. When the diffused dopant atoms exit the back surface 15 of the substrate 16, most of the dopant atoms flow downwardly through the passages 118 and 120 into the lower reactor chamber 4 by forcing an inert gas into the gap region 152. Washed away. Thus, the diffused dopant atoms are substantially prevented from flowing up around the edge 17 of the substrate into the upper reactor chamber 2 and redepositing on the surface 155 of the substrate 16. Furthermore, if some out-diffusion dopant atoms flow radially outwardly through the spacer ring 110 and around the edge 17 of the substrate, the momentum of the inert gas flowing upward around the edge 17 Such dopant atoms can be blown away from the surface 155 of the substrate and carried away by the normal flow of reaction gases and deposition byproducts in the upper reactor chamber 2. The pressure and flow rate of the inert gas injected upward into the region 152 can be adjusted to reduce or minimize the likelihood that such dopant atoms will redeposit on the surface 155 of the substrate.

  The support system 140 is a significant improvement over prior art systems because, for example, the hollow support spider 22 can controllably force the inert gas directly into the gap region 152. Based on the specific design of the substrate holder 100 and spider 22, the inert gas may be supplied directly into any number of selected passages 116 at a desired location in the central portion 102 of the holder 100. This system more effectively reduces or prevents backside deposition and autodoping.

  Referring to FIG. 1, as described above, the partition 36 of the reactor 10 often does not completely impede the flow of reaction gas from the upper reactor chamber 2 into the lower chamber 4. In some prior art systems, such reactive gases under the substrate holder may flow on the backside of the substrate and deposit on the substrate. However, the substrate support system 140 shown in FIGS. 7 and 8 solves this problem. By forcing the inert gas into the support spider 22, it is preferred that the inert gas flow downward through the passages 118 and 120 of the holder 100, so that the reaction gas is directed upward to the back surface 154 of the substrate. Flow is substantially suppressed. The risk of this mode of backside deposition can also be reduced by maintaining a pressure differential between the upper chamber 2 and the lower chamber 4. The pressure in the latter is maintained higher than the former pressure. This pressure difference can be created by introducing some inert gas directly into the lower chamber 4 and reducing the size of any outlet from the chamber 4 or removing the outlet completely. This extra inert gas may be an alternate flow path from the gas transporter 144 to the chamber 4 (ie, a flow path where the inert gas can flow into the chamber 4 without flowing through the gap region 152), or a separate gas inlet Can be introduced into the chamber 4.

  It will also be appreciated that the substrate support system 140 may be used to remove the native oxide layer from the back surface 154 of the substrate 16. A cleaning gas (e.g., hydrogen gas) may be supplied up through gas transporter 144, spider 22, and passage 116 into gap region 152. The cleaning gas removes the oxide layer from the back surface 154. Next, excess cleaning gas, and by-products from the removal of oxide, pass from the gap region 152 through the passages 118 and 120, and to some extent (via the channel 126 between the vanes 124, FIG. ) Outflows around the periphery 17 of the substrate 16. The removal of the oxide layer can be performed simultaneously on the back surface 154 and the front surface 155 of the substrate 16. Thus, the above-described substrate backside cleaning operation may include simultaneously introducing a generally horizontal flow of cleaning gas above the substrate 16 in the upper reactor chamber 2. The spider 22, holder 100, and substrate 16 are preferably rotated about a central vertical axis during the cleaning operation, which improves the removal of the oxide layer uniformly and completely. Again, the angled spacer vanes 124 help by-products from the oxide removal and excess cleaning gas flow radially outward through the channels 126. In some embodiments, the oxide layer is almost completely removed from the substrate backside 154 by “baking” (ie, exposing the backside 154 to the cleaning gas) for less than 2 minutes, in some cases 40-60 seconds. I knew I would get it.

  One skilled in the art will appreciate that other substrate holders may be used in place of the holder 100, particularly substrate holders having a gap region 152 between the back surface of the substrate 16 and the top surface of the holder. For example, substrate holders having different types of spacer elements (eg, spacer lips attached to the holder surface, spacer nodes or pins, annular lips with several gas flow channels, etc.) may be used.

  9 and 10 show a substrate support system 200 according to another embodiment of the present invention. The system 200 includes a generally bowl-shaped or cup-shaped substrate holder support 204 instead of the support spider 22. FIG. 9 is a side sectional view of the entire system 200, and FIG. 10 is a plan view of only the holder support 204. The system 200 can support the substrate 16 during substrate processing (eg, CVD such as epitaxial deposition) or removal of an oxide layer. Similar to the system 140 described above, the present system 200 prevents or reduces the degree of contact between the backside of the supported substrate 16 and the process gas. The system 200 also reduces or prevents autodoping. Similar to the support spider 22, the substrate holder support 204 can be attached to the gas transporter 144 (eg, a rotatable vertical tube) and can engage and support the substrate holder 100. The substrate holder support 204 can rotationally couple the substrate holder 100 to the tube 144 so that the tube, the support 204 and the holder 100 rotate simultaneously.

  In the illustrated embodiment, the substrate holder support 204 includes a generally flat base 251 that extends from the upper end of the gas transport tube 144 to a generally vertical and preferably annular structure 252. The structure 252 preferably includes a wall. The substrate holder 100 can be mounted on the upper edge 262 of the vertical wall 252, preferably fixedly. The upper edge 262 is preferably formed to restrict the flow of fluid across the interface between the upper edge 262 and the lower surface 106 of the holder 100. The wall 252 preferably defines a relatively large top opening in the holder support 204 that is at least under most of the bottom surface 106 of the holder 100. This upper opening defines a certain proportion of the size of the substrate 16 that is specifically designed to be supported by the substrate holder 100. This proportion is preferably 50 to 120%, but may be in the range of 70 to 120%, 95 to 120%, 50 to 100%, or 70 to 100%. The chamber 260 is defined between the upper surface 265 of the base 251 and the lower surface 106 of the central portion 102 of the holder 100. The passage 240 of the substrate holder 100 provides fluid communication between the chamber 260 defined between the holder 100 and the holder support 204 and the gap region 252. The holder support 204 can be assembled from a material with suitable properties such as quartz, graphite coated with silicon carbide, or other material. One skilled in the art can achieve any of the desired objectives of the present invention by determining the appropriate combination of material type, thickness, and shape as described herein.

  In the embodiment shown here, the substrate holder 100 is substantially the same as the substrate holder 100 shown in FIGS. However, those skilled in the art will appreciate that other substrate holders may be used, particularly substrate holders having a gap region 252 between the back surface of the substrate 16 and the top surface of the holder. For example, substrate holders having different types of spacer elements (eg, spacer lips, spacer nodes or pins attached to the holder surface, annular lips with several gas flow channels, etc.) may be used. One skilled in the art will also understand that for the purposes of this embodiment, the recess 114 in the holder 100 may be altered or omitted if there is no spider arm that engages the recess 114 in the holder 100. Further, in this embodiment, there are no relevant differences between the aforementioned passages 116, 118, and 120. Therefore, in this embodiment, the passage of the holder 100 is collectively referred to as a passage 240 having an upper end portion 242 and a lower end portion 244. As in the previous embodiment, the passage 240 is preferably angled or formed to minimize the direct impact of gas on the substrate back surface 154.

  The substrate holder 100 can be removably or permanently coupled to the substrate holder support 204, which is then coupled to the gas transporter 144. The substrate holder 100 is preferably supported in a fixed manner by the substrate holder support portion 204 so that substantially no slip occurs between them and the substrate holder 100 rotates at the same time. For example, it is preferable that the substrate holder 100 can be placed on the substrate holder support portion 204, and as a result, the substrate holder 100 can be lifted from the substrate holder support portion 204. In other embodiments, the bottom surface of the substrate holder 100 is connected to the upper edge of the holder support 204 (eg, by a snap connection, a pin or hole connection, or other suitable means) to support the holder 100 as a holder support. It is formed so as to lock with the portion 204 in a rotational manner.

  The substrate holder support portion 204 shown here includes a base 251 and an annular vertical wall 252. Base 251 extends from wall 252 to flange 253, which engages gas transporter 144. In the embodiment shown here, the base 251 extends in the horizontal direction from the flange 253 and has a shape substantially similar to the shape of the holder 100. However, the base 251 may be any shape suitable for a portion of the holder support 204 (eg, the wall 252) to engage the lower surface 106 of the substrate holder 100. The wall 252 of the substrate holder support part 204 extends upward from the periphery of the base 251. The wall 252 is sized and shaped to hold and support the substrate holder 100 that supports the substrate 16 thereon. In the illustrated embodiment, the wall 252 is oriented generally perpendicular to the base 251 and is vertical. Although not shown, the wall 252 may be oriented at any angle relative to the base 251 and the substrate holder 100 (eg, a cone, for example) depending on the desired distance between the base 251 and the lower surface 106 of the substrate holder 100. It may be shaped.) Furthermore, the wall 252 may have any height so as to provide a desired distance between the base 251 and the substrate holder support 204.

  The substrate holder support 204 shown here preferably prevents the back surface 154 of the substrate 16 from being directly exposed to the radiant heating element 14 (FIG. 1) disposed below the holder 100. In particular, the holder support 204 blocks direct thermal energy through the passage 240 of the holder 100. This helps keep the substrate 16 free of hot spots, which can adversely affect the uniformity of the material layer deposited on the substrate.

  In the illustrated embodiment, the chamber 260 is generally cylindrical. In one embodiment, the chamber 260 has a generally constant height. In other embodiments, the height of the chamber 260 varies radially. For example, the height of the chamber 260 may be decreased radially outward. However, the chamber 260 may be any profile that is desirably suitable height. In the embodiment shown here, the cross-sectional outlines of the base 251 and the wall 252 are generally U-shaped. Alternatively, the contour may be V-shaped, W-shaped, semi-circular, or combinations thereof, or any other suitable shape.

  The size and shape of base 251 and wall 252 can be varied to make chamber 260 the desired size and shape. In the illustrated embodiment, for example, the substrate holder support 204 is generally bowl-shaped or cup-shaped such that the chamber 260 is generally cylindrical with a substantially uniform height equal to the height of the wall 252. The diameter of the base 251 can be selected by placing the edges or top 262 of the wall 252 in the desired arrangement. In the embodiment shown here (FIG. 9), the size of the base 251 is such that the wall 252 is disposed on all radially outer sides of the passage 240.

  The substrate holder support 204 can be attached to the upper end or outlet 143 of the gas transporter 144. In one embodiment, the gas transporter 144 is a hollow tubular member that supplies a fluid (eg, a cleaning gas and / or an inert gas) to the substrate holder support 204. The tube 144 includes a tube passage 210 that extends through the tube 144 to the chamber 260. The gas transporter 144 is preferably capable of rotating so as to rotate the holder support 204, the holder 100, and the substrate 16 simultaneously. Optionally, the gas transporter 144 may be moved vertically to move the holder 100, holder support 204, and substrate 16 upward and / or downward. It will be appreciated that the gas transporter 144 can move the holder 100 and the holder support 204 when the substrate 16 is not located in the substrate support system 200.

  In the illustrated embodiment, a relatively narrow passage 240 may provide fluid communication between the gap region 152 and the chamber 260. That is, the gas can move between the gap region 152 and the chamber 260 via the passage 240. In other embodiments, such fluid communication may be enabled by other types of passages such as a slotted ring or a single large hole in the central portion 102 of the holder 100.

  The substrate holder 100 and the substrate holder support portion 204 can be made of materials having the same or different coefficients of thermal expansion. In one embodiment, the holder 100 and the holder support 204 have the same coefficient of thermal expansion so as to reduce relative movement between the lower surface 106 of the holder 100 and the upper portion 262 of the wall 252.

  In one embodiment, the position of the holder 100 relative to the holder support 204 is maintained by frictional engagement between the upper portion 262 of the wall 252 of the holder support 204 and the lower surface 106 of the holder 100. It is preferable that the holder 100 is disposed around the rotation axis of the gas transporter 144. Optionally, the holder 100 may comprise means for centering itself relative to the holder support 204. For example, the lower surface 106 may include a ridge or groove that is formed to engage the upper portion 262 so that the position of the holder 100 relative to the holder support 204 remains the desired position. Or move to the desired position. At least one of the upper portion 262 and the lower surface 106 is provided with a protrusion, a spline, a groove, a rough surface, or the like for preventing slippage between the holder 100 and the holder support portion 204, particularly while rotating the holder 100 and the holder support portion 204. Or may have other features on the face. Optionally, a seal may be formed between the upper portion 262 and the lower surface 106 to maintain the integrity of the chamber 260. For example, the seal may inhibit or prevent processing gas in the lower reactor chamber 4 from entering the chamber 260.

  In the embodiment shown here, the substrate holder 100, the substrate holder support part 204, and the gas transporter 144 are formed so as to suppress back surface deposition described later. During substrate processing, an inert gas is directed upward through the gas transporter 144 into the chamber 260. Inert gas flows through chamber 260 and fills chamber 260. Some of the inert gas flows from the passage 240 into the gap region 152. The inert gas in the gap region 152 forms a “gas curtain” that allows the processing gas in the upper reactor chamber 2 above the substrate 16 to pass around the substrate edge 17 to the gap region 152. Control or prevent spillage. In particular, the inert gas in the gap region 152 is at least slightly higher in pressure than the process gas in the chamber 2 above the substrate 16, so that there is an upward gap between the substrate holder 100 and the substrate 16 around the substrate edge 17. Easy to flow to. In the illustrated embodiment, the inert gas is radially directed through the channel 126 (FIGS. 5 and 6) between the spacer blades 124 as described above in connection with the embodiment of FIGS. By flowing outward, it leaves the gap region 152 and then flows upward around the substrate edge 17. Further, as described above, the angled spacer vanes 124 facilitate the flow of inert gas radially outwardly through the channel 126, thereby allowing the gas (reactive gas or inert gas) to flow through them. Flowing radially inward between is substantially suppressed or prevented.

  If the pressure in the gap region 152 is too high, the substrate 16 may lift and / or slide relative to the substrate holder 100, which is undesirable. If the pressure in the gap region 152 is too low, the reaction gas above the substrate 16 may flow out from around the substrate edge 17 into the gap region 152. The pressure of the inert gas in the gap region 152 is slightly or substantially higher than the pressure of the reaction gas in the upper reactor chamber 2, but is so high that the substrate 16 is lifted and / or slid relative to the substrate holder 100. It is preferable not to be. In selecting the pressure of the gas in the gap region 152, the purpose is to cool the substrate (locally or differently), or without incurring the substantial risk of the substrate lifting or sliding. To substantially prevent or reduce the flow of reactant gas from the chamber 2 around the edge 17 into the gap region 152. Those skilled in the art will be able to select an appropriate gas pressure within the gap region 152 taking these into account. In one embodiment, it can be envisaged that the inert gas flowing into the chamber 260 is supplied at a relatively low flow rate, typically 0.4 to 2.0 slm. In the preferred implementation, little or no reactive gas in the chamber 2 flows into the gap region 152 during substrate processing.

  Compared to the gas transport spider 22 described above, which directs the inert gas directly into the passage 116 (FIGS. 2, 3 and 8) of the substrate holder 100, the substrate holder support 204 provides localized cooling of the substrate 16. Is preferably reduced. This is because the gas transport spider 22 guides the ejection of the inert gas directly to a specific location on the back surface 154 of the substrate, but the holder support portion 204 does not. The holder support 204 helps to move the inert gas more slowly through the passage 240 so that the gas does not impinge on the substrate back surface 154 at that momentum.

  Referring to FIG. 1, as described above, the partition 36 of the reactor 10 often does not prevent any reaction gas from flowing from the upper reactor chamber 2 into the lower chamber 4 at all. In some prior art systems, such reactive gases under the substrate holder may flow to the substrate backside and deposit on it. However, the substrate support system 200 shown in FIGS. 9 and 10 solves this problem. The substrate holder support 204 preferably substantially suppresses or prevents such reactive gas in the chamber 4 from flowing from the passage 240 into the gap region 152. In particular, the base 251 and the annular wall 252 suppress the flow of these reaction gases into the chamber 260. Optionally, sufficient compression to prevent or inhibit reaction gas in the lower chamber 4 from flowing into the chamber 260 from between the upper portion 262 of the wall 252 and the lower surface 106 of the substrate holder. Can be performed on the inert gas. For example, the pressure of the inert gas in the chamber 260 may be maintained at a pressure that is at least equal to or slightly higher than the pressure of the gas in the lower chamber 4. Furthermore, the present system 200 may instead be used in a reactor 10 that does not include a partition 36 that separates the upper chamber 2 and the lower chamber 4. By omitting partition 36, cost and complexity are reduced and some processing problems such as devitrification and undesirable coating on quartz partition 36 may be avoided.

The substrate support system 200 also facilitates the removal of the native oxide layer from the substrate back surface 154. The oxide layer may be removed from the substrate back surface 154 by injecting a cleaning gas (such as H ₂ ) upward through the gas transporter 144. Excess cleaning gas and by-products from oxide removal may be exhausted from the system 200 by flowing upwards around the substrate edge 17 into the upper reactor chamber 2. The rotation of the substrate holder 100 can help in this way flow of cleaning gas and by-products from oxide removal. In general, additional cleaning gas is simultaneously supplied above the substrate 16 in the upper chamber 2 to simultaneously remove the oxide layer from the surface 155 of the substrate 16.

The inert gas flowing through the substrate support system 200 is preferably a silicon-free inert gas such as hydrogen gas. It will be appreciated that hydrogen gas can act as an inert purge or sweep gas and as a cleaning gas. When there is no oxide layer on the silicon wafer 16 under certain temperature conditions, the hydrogen gas is inactive. When the oxide layer (SiO ₂ ) is on the silicon wafer 16, the hydrogen gas chemically reduces the oxide layer to remove oxygen and leave silicon on the wafer surface. In one embodiment, the inert gas is substantially all hydrogen. However, other gas or gases may flow through the substrate support system 200.

  The pressure and flow rate of the gas flowing through the gas transporter 144 into the chamber 260 and the gap region 152 may be adjusted based on the size and shape of the substrate 16, substrate holder 100, and holder support 204. The gas pressure and flow rate may also be adjusted based on gas flow parameters and characteristics in the lower reactor chamber 4. This naturally depends on which of the plurality of passages 240 has a lower end portion 244 (for example, FIG. 11 described later) disposed on the radially outer side of the annular wall 252 of the holder support portion 204. .

  FIG. 11 shows a substrate support system 300 according to another embodiment of the present invention. Many of the elements of the system 300 are similar to the substrate support system 200 described above, and thus will not be described in detail. As described below, the substrate support system 300 still more effectively reduces autodoping while preventing or significantly reducing the backside deposition of the substrate.

  The substrate support system 300 includes a substrate holder support 304 that is sized and shaped to support the substrate holder 100. As described above, the holder support 304 includes a flange 253 that is configured to be attached to the upper end or inlet of a gas transporter (eg, a rotatable vertical tube). The size of the holder support portion 304 is such that the arrangement of the lower opening 344 of the at least one passage 340 is such that gas flowing downward from the opening 344 does not flow into the chamber 260. In the embodiment shown here, the opening 344 is disposed radially outward of the annular wall 252 and the annular wall 252 is preferably generally circular. The at least one complete set or ring of the plurality of lower openings 344 of the passage 240 prevents the gas exiting the openings 344 from flowing into the chamber 260 (eg, all the openings 344 have the diameter of the annular wall 252). It is preferable to be arranged (outside in the direction). Optionally, the lower opening 344, which is a plurality of rings comprising a plurality of passages 340, is disposed radially outward of the annular wall 252. This at least one outermost set or ring comprising a plurality of passages 340 is preferably arranged substantially evenly in the peripheral region of the substrate holder 100. During substrate processing, the inert gas flowing down through the set or ring of at least one passage 340 removes most or substantially all of the diffusing dopant atoms from the gap region 152, as described below. Push into lower chamber 4 of reactor below 100. Alternatively, the passages 340 arranged on the outer side in the radial direction of the substrate holder support 304 may be arranged at irregular intervals around the periphery of the base plate 251. In the following description, reference numeral 240 refers to a passage in which a lower end or opening 244 is arranged to discharge gas into the holder support 304, and reference numeral 340 refers to the chamber 4 outside the holder support 304. A passage in which a lower end portion or an opening portion 344 is disposed so as to discharge the gas.

  In operation, inert gas can be delivered to the flange inlet 253 through the gas transporter. The inert gas flows upward into a chamber 260 defined between the substrate holder support 304 and the substrate holder 100. Next, the inert gas flows through the passage 240 into the gap region 152 above the substrate holder 100. The inert gas flows through the entire gap region 152 and substantially fills the gap region 152. A significant portion of the inert gas in the gap region 152 flows down into the lower reactor chamber 4 through the passage 340. Accordingly, the gap region 152 provides fluid communication between the chamber 4 and the chamber 260. The number and arrangement of the passages 340 may be determined based on the desired flow parameters of the inert gas in the gap region 152 and / or the chamber 4. The dopant atoms that diffuse through the substrate 16 and flow out of the substrate back surface 154 are preferably substantially swept away from the gap region 152 by flowing an inert gas downward from the passage 340 into the chamber 4. This substantially prevents or reduces the amount of autodoping on the top surface of the substrate 16. The pressure of the inert gas in the gap region 152 is preferably slightly or substantially higher than the pressure in the chamber 4 such that the inert gas is forced into the chamber 4 from the passage 340. In the preferred implementation, little or no gas in the chamber 4 flows from the passage 340 into the gap region 152.

  With continued reference to FIG. 11, some of the inert gas in the gap region 152 may flow radially outwardly through the ring 110 of the spacer vane 124 and upward around the substrate edge 17 (FIG. 5, FIG. 6). This part of the inert gas can drive some of the diffusing dopant atoms upwards into the upper reactor chamber 2, which poses a risk of autodoping. This risk of autodoping can be reduced by adjusting the size of the passage 340 relative to the size of the channel 126 of the vane 124 (FIGS. 5 and 6). If the sum of the narrowest cross sections of each passage 340 is greater than the sum of the narrowest cross sections of each channel 126, the inert gas exits the gap region 152 and exits the passage 340 rather than the channel 126. Will tend to “choose”. In other words, if the plurality of passages 340 add up to a wider flow path than the channel 126 (ie, the flow cross-sectional area is wider), the risk of autodoping is reduced. Those skilled in the art will appreciate that the risk of autodoping further decreases as the imbalance between the channel width of the passage 340 and the channel 126 channel increases.

  As described above, the ring 110 of the spacer blade 124 may optionally be replaced with a rigid substrate support shelf. In selecting from these two options, one skilled in the art can balance the need for temperature uniformity in the wafer with the need to reduce autodoping. A rigid support shelf can make autodoping less likely because it blocks the flow of dopant atoms that would otherwise flow around the substrate edge 17. The spacer blade 124 minimizes heat conduction between the substrate holder and the substrate 16, thus improving temperature uniformity. It should be noted that even when using vanes 124, autodoping can be adequately reduced by increasing the flow of inert gas that forces the system through. It will also be appreciated that in certain implementations, a rigid substrate support shelf top can better control backside deposition.

  With continued reference to FIG. 11, the risk of autodoping can also be reduced by properly controlling the pressures in regions 152, 2, and 4. The pressure of the inert gas in the gap region 152 is preferably larger than the pressure in the upper reactor chamber 2 and the lower reactor chamber 4. If not, the inert gas will not flow into chambers 2 and 4. Optionally, the pressure in the upper chamber 2 is maintained slightly or substantially higher than the pressure in the lower chamber 4 so that the inert gas in the gap region 152 is allowed to flow through the ring 110 of the spacer vane 124. It is preferable to flow through the passage 340 rather than (FIGS. 5 and 6).

  Of course, the goal of letting most of the inert gas out of the gap region through the passage 340 is to allow some of the inert gas to be removed from the ring 110 of the spacer vane 124 so as to prevent backside deposition of reactant gas from the upper chamber 2. It is preferable to properly balance the achievable goal of flowing through. In adjusting the size of the passage 140 and channel 126 and the pressure in the regions 152, 2, and 4, those skilled in the art will appropriately balance these goals during the implementation of the substrate support system 300.

  The substrate support system 300 of FIG. 11 can also substantially prevent backside deposition by forcing reactive gases down through the passage 340. The reaction gas from the upper reactor chamber 2 is particularly suitable when the inert gas in the gap region 152 does not flow radially outward through the ring 110 of the vane 124 (FIGS. 5 and 6). It is possible to flow downward between the shoulder portions 108 of the two. When such a reactive gas flows radially inward through the channel 126 between the vanes 124, the forced flow of inert gas causes substantially all of the reactive gas to flow downwardly from the passage 340 into the lower reactor. It is preferable to flush into the chamber 4. As such, the system 300 substantially prevents or reduces the extent to which the outflowing reactive gas deposits on the back surface 154 of the substrate 16. Preferably, at least one ring or set of multiple passages 340 is placed in close proximity to the thermal insulation groove 30 to minimize the peripheral area of the substrate back surface 154 where reaction gases may be deposited. . The outermost ring or set of passages 340 is preferably arranged so that any reaction gas deposited on the backside is deposited only in the exclusion zone of the substrate 16.

  In one embodiment, the substrate support system 300 is formed such that a single passage 340 having a lower opening 344 is disposed, which allows gas flowing out of the lower opening 344 to flow downward. Such that it flows into the lower reactor chamber 4 outside 304. With reference to FIG. 11, there is preferably only one passage 340 having a lower end 344 that is radially outward of the annular wall 252. In a preferred implementation, the inert gas flowing down through the single passage 340 forces most or substantially all of the outwardly diffusing dopant atoms from the gap region 152 to the lower chamber 4. Since there is only one passage 340 in the present system 300, in order to more effectively push dopant atoms and / or reactant gases flowing downward into the single passage 340 (shown in FIGS. 9 and 10). Preferably, the inert gas is injected into the holder support 304 at a higher pressure (compared to the inert gas pressure of the system 200). It is also preferable to increase the size of the single passage 340 to some extent. With this embodiment having only one passage 340, more inert gas will flow upward around the substrate edge 17, thereby more effectively preventing or reducing the backside deposition of reactive gases. It is preferable to do.

  It will be appreciated that the substrate support system 300 may be used to remove the oxide layer from the substrate back surface 154 by injecting a cleaning gas upward into the flange inlet 253 of the substrate holder support 204. The cleaning gas flows upward through the chamber 260 and passage 240 to remove the oxide layer from the back surface 154. By-products from excess cleaning gas and oxide removal flow radially outwardly into the lower chamber 4 through the passage 340 and / or through the ring 110 of the spacer blade 124 into the upper chamber 2. Exit the system 300. A cleaning gas may also be introduced simultaneously into the chamber 2 to remove the oxide layer from the surface 155 of the substrate 16.

  With respect to the above-described embodiment 200 (FIGS. 9 and 10) and embodiment 300 (FIG. 11), the substrate holder supports 204, 304 allow gas to flow upward into the lower ends of various numbers of passages within the substrate holder 100. Can be configured to transport. This number is at least 9, but can preferably be in the range of 9-250, 6-225, 20-250, 50-200, 100-200, or 100-250.

  Three different generic embodiments of the substrate support system have been described above. That is, (1) a system 140 (FIGS. 7 and 8) including a hollow support spider 22 and (2) a system 200 (FIGS. 9 and 10) including a substrate holder support portion 204, which supports the substrate holder. In part 204, all of the plurality of passages 240 of the substrate holder 100 are in fluid communication with the chamber 260, the chamber 260 being defined between the holder 100 and the holder support 204, and (3) A system 300 (FIG. 11) that includes a substrate holder support 304, in which one or more passages 340 in the holder 100 allow gas to flow outside the chamber 260 within the lower reactor chamber 4. And the system 300 arranged to discharge downward. Those skilled in the art will appreciate from the teachings herein that these embodiments provide somewhat different advantages from each other. System 140 appears to be most effective for autodoping. The reason is that there are a relatively large number of passages 118 and 120 through which outwardly diffusing dopant atoms can be pushed down into the lower chamber 4. System 200 appears to be most effective for backside deposition. This is because only the outflow path for the inert gas injected into the holder support portion 204 is radially outward from the ring 110 of the spacer blade 124, so that the reaction gas moves downward around the substrate edge 17. The flow can be better suppressed. Further, the base 251 of the holder support portion 204 covers all the lower end portions 244 of the plurality of passages 240 of the holder 100, so that the reaction gas in the lower reactor chamber 4 passes through such passages upwardly on the substrate back surface. 154 is prevented from flowing.

  Compared to substrate support systems 140 and 200, substrate support system 300 can more effectively balance the two objectives of suppressing backside deposition and autodoping in some implementations. Compared to system 140, system 300 appears to more effectively suppress backside deposition. This is because (1) there are fewer passages of the holder 100 in which the inert gas in the gap region 152 can flow downward into the lower reactor chamber 4, and the inert gas more easily flows upward around the substrate edge 17. (2) the base 251 of the holder support 304 is configured so that the reaction gas in the chamber 4 is moved upward from the passage of the holder 100 to the substrate back surface 154. By substantially impeding the flow. Compared to system 200, system 300 appears to more effectively suppress autodoping. This is due to the presence of at least one passage 340 through which dopant atoms can be swept down into the chamber 4.

  The methods described and illustrated herein are not limited to the exact order of steps described herein. It is not necessarily limited to performing all the steps. In practicing the embodiments and methods of the present invention, the steps or events may be performed in other orders, or not all of the steps may be performed, or the steps may be performed simultaneously.

  Moreover, those skilled in the art will appreciate that various features may be interchanged with different embodiments. Similarly, one of ordinary skill in the art can perform the methods according to the principles described herein by combining and adapting the various features and steps described above and other known equivalents of each such feature or step.

  While the invention has been disclosed in connection with certain embodiments and examples, the invention extends beyond the specifically disclosed embodiments to other alternative embodiments and / or uses and obvious modifications and equivalents. Will be understood by those skilled in the art. Accordingly, the present invention is not limited to the specific disclosures of preferred embodiments herein.

FIG. 3 is a schematic cross-sectional view of an exemplary reaction chamber that supports a substrate on a substrate holder. It is a top perspective view of the substrate holder concerning one embodiment of the present invention. FIG. 3 is a bottom perspective view of the substrate holder of FIG. 2. FIG. 4 is a partial sectional view of the substrate holder of FIG. 2 taken along line 4-4 of FIG. FIG. 3 is an enlarged view of a part of the substrate holder of FIG. 2 indicated by an arrow 5 in FIG. 2. It is a top view of a part of substrate holder concerning other embodiments of the present invention. 1 is a plan view of a substrate support system according to a first embodiment of the present invention. FIG. 8 is a cross-sectional view of the substrate support system of FIG. 7 taken along line 8-8 of FIG. It is a sectional side view of the board | substrate support system which concerns on the 2nd Embodiment of this invention. It is a top view of the substrate holder support part of the substrate support system of FIG. It is side sectional drawing of the board | substrate support system which concerns on the 3rd Embodiment of this invention.

Claims (50)

A substrate support system,
A substrate holder for holding the substrate;
A hollow support member having an inlet adapted to engage a gas transporter outlet to facilitate the flow of gas from the gas transporter;
With
The substrate holder is
A central portion having an upper surface, a lower surface, and a plurality of open passages extending from the upper surface to the lower surface;
At least one spacer having an upper support surface extending upward from the central portion and raised above the upper surface of the central portion, wherein the upper support surface of the at least one spacer has a gap region of the central portion; At least one spacer formed to support the periphery of the substrate such that it exists between a top surface and a bottom surface of the substrate;
Including
The hollow support member has one or more open upper ends adapted to support the lower surface of the central portion of the substrate holder, wherein the one or more open upper ends are the substrate Formed in the lower end of one or more of the plurality of passages in the central portion of the holder to transport gas upward, wherein at least one of the passages is a region outside the hollow support member A substrate support system having a lower end opening.   The substrate support system according to claim 1, wherein an upper surface of a central portion of the substrate holder is concave.   The substrate support system according to claim 1, wherein an upper surface of a central portion of the substrate holder is substantially flat.   The substrate support system according to claim 1, wherein the at least one spacer includes a plurality of spacers, and the plurality of spacers surround a periphery of a central portion of the substrate holder.   The substrate support system according to claim 1, wherein the substrate holder includes a susceptor.   The substrate support system of claim 1, wherein the gas transporter includes a substantially vertical hollow tube, and the outlet of the gas transporter includes an open upper end of the tube.   The substrate support system according to claim 1, wherein the gap region has a substantially uniform height.   The inlet of the hollow support member engages the outlet of the gas transporter such that the hollow transport member and the substrate holder rotate with the gas transporter by rotating the gas transporter about a vertical axis. The substrate support system of claim 1, formed as described above.   The substrate support according to claim 1, wherein the hollow support member is formed to guide gas to one or more passages of the plurality of passages of the substrate holder when the substrate holder is placed on the hollow support member. system.   The at least one spacer includes a ring of a plurality of vanes spaced apart and generally parallel to each other, each vane being angled with respect to a center of the ring of the plurality of vanes. The substrate support system of claim 1.   The substrate support system of claim 10, wherein the blades are straight.   The substrate support system according to claim 10, wherein the blade is curved.   The at least one spacer includes a plurality of spacers, and when the upper support surface of the spacer supports the peripheral edge of the substrate, the hollow support member and the substrate holder are arranged around the vertical central axis in the first rotation direction. By rotating, the spacer substantially hinders the flow of gas inward in the radial direction between the spacers, and the hollow support member and the substrate holder move around the vertical central axis in the second rotational direction. 2. The rotation causes the spacer to substantially prevent a gas flow outwardly in a radial direction between the spacers, and the second rotation direction is opposite to the first rotation direction. A substrate support system according to claim 1.   The hollow support member includes a hollow main body and a plurality of tubes extending generally radially outward and upward from the hollow main body, and an inlet of the hollow support member is disposed substantially at a lower surface or an end of the hollow main body, The substrate support system according to claim 1, wherein one or more open upper ends of the hollow support members include the upper end of the tube.   The passage includes a first set, a second set, and a third set of a plurality of passages, and the plurality of passages of the first set are formed to receive gas from an upper end portion of the pipe, and The plurality of sets of passages are radially inward of the first set of the plurality of passages, and the third set of passages of the plurality of passages are the first set of the plurality of passages. Each of the passages of the second set includes an upper end portion that is radially outward of a lower end portion of the passage, and each of the passages of the third set has a diameter of a lower end portion of the passage. The substrate support system according to claim 14, wherein the substrate support system has an upper end portion located on an inner side in the direction.   The substrate support system according to claim 14, wherein the plurality of tubes includes three tubes.   Each upper end of the tube is formed to be received in a corresponding recess in the lower surface of the central portion of the substrate holder, the corresponding recess being at least one of a plurality of passages in the central portion of the substrate holder. The substrate support system of claim 14, comprising a lower end of the passage.   One or more open upper ends of the hollow support member comprise a single open end defined by an annular wall, the annular wall being formed to support the substrate holder in a fixed manner. The substrate support system of claim 1, further comprising an upper edge.   The substrate support system of claim 18, wherein the hollow support member includes a generally horizontal base member and the annular wall, the annular wall extending upward from the base member.   The substrate support system according to claim 18, wherein the one open end portion supplies gas to a lower end portion of at least nine passages of the plurality of passages.   The substrate support system according to claim 18, wherein at least one lower end portion of the lower end portions of the plurality of passages is disposed on a radially outer side of the annular wall.   The substrate support system according to claim 1, wherein the substrate holder further includes an annular shoulder surrounding the at least one spacer.   The substrate support system according to claim 1, wherein the plurality of passages includes 9 to 250 passages. ^2. The substrate support system according to claim 1, wherein a density of a passage on a lower surface of a central portion of the substrate holder is 0.01 to 3.0 per 1 cm ² .   The substrate support system according to claim 1, further comprising the gas transporter.   The inlet of the hollow support member is adapted to engage the outlet of the gas transporter in a substantially fluid-tight manner, and one or more open upper ends of the hollow support member are formed on the substrate holder. The substrate support system of claim 1, wherein the substrate support system is adapted to transport gas upward substantially fluid tightly into one or more of the central plurality of passages.   The substrate support system of claim 1, wherein one or more of the plurality of passages is oriented at an angle with respect to vertical. A substrate support system,
A substrate holder for holding the substrate;
A hollow support spider,
With
The substrate holder is
A central portion having an upper surface, a lower surface, and a plurality of passages extending from the upper surface to the lower surface;
A plurality of spacers having an upper support surface extending upward from the central portion and raised above the upper surface of the central portion;
Including
The upper support surface of the spacer is formed to support the peripheral edge of the substrate such that a gap region exists between the upper surface of the central portion and the bottom surface of the substrate.
The hollow support spider is
The hollow manifold having an inlet adapted to engage an outlet of the gas transport to facilitate the flow of gas from the gas transport;
A plurality of hollow arms extending generally radially outward and upward of the manifold;
Including
The hollow arm is configured to receive a gas flow from the manifold and has an open top end adapted to support a lower surface of a central portion of the substrate holder, and the hollow arm opening. A substrate support system, wherein the upper end is configured to transport gas upward into a subset of the plurality of passages in the central portion of the substrate holder.   The lower surface of the central portion includes a plurality of recesses, and each recess is sized and shaped to receive one of the upper end portions of the arm and includes a lower end portion of at least one passage of the passage. 29. A substrate support system according to claim 28. A substrate support system,
A substrate holder for holding the substrate;
A hollow support member;
With
The substrate holder is
A generally flat central portion having an upper surface, a lower surface, and a plurality of open passages extending from the upper surface to the lower surface;
A plurality of spacers having an upper support surface extending upward from the central portion and raised above the upper surface of the central portion;
Including
The upper support surface of the spacer is formed to support the peripheral edge of the substrate such that a gap region exists between the upper surface of the central portion and the bottom surface of the substrate.
The hollow support member is
A lower base member having an inlet adapted to engage with an outlet of a gas transporter to facilitate gas flow from the gas transporter into the hollow support member;
An annular wall extending upward from the base member;
Including
The annular wall includes an upper edge formed to support the bottom surface of the substrate holder so that a gas within the annular wall and between the base member and the bottom surface of the substrate holder is Flow is substantially prevented between the upper edge of the annular wall and the bottom surface of the substrate holder, the upper edge defining an upper opening of the hollow support member, the upper opening being a gas A substrate support system configured to transport the upper side upward into the lower end of at least nine of the plurality of passages in the central portion of the substrate holder.   31. The substrate support system according to claim 30, wherein the upper opening of the hollow support member is below at least a majority of the bottom surface of the substrate holder.   31. The substrate support system according to claim 30, wherein at least one of the plurality of passages in the central portion of the substrate holder has a lower end portion opened to a region outside the hollow support member.   31. The substrate support system according to claim 30, wherein all of the plurality of passages in the central portion of the substrate holder have a lower end portion that opens to the inside of the hollow support member. A substrate holder for holding a substrate,
A first set of open passages extending from the upper surface to the lower surface; and a second set of open passages extending from the upper surface to one of the recesses in the lower surface, respectively. A central portion having a set;
A plurality of spacers having an upper support surface extending upward from the central portion and raised above the upper surface of the central portion;
With
Each recess is adapted to receive one of a corresponding plurality of upper ends of the tubular arms of the hollow support member, the upper ends supporting the central portion and allowing gas to pass through a second of the plurality of passages. Formed to transport upward in the set,
The upper support surface of the spacer is a substrate holder that is formed so as to support the periphery of the substrate such that a gap region exists between the upper surface of the central portion and the bottom surface of the substrate. A hollow support member for supporting a substrate holder formed to support a substrate during substrate processing, the hollow support member,
A base member having a lower inlet adapted to engage the upper end of the tube to facilitate upward gas flow from a hollow tube into the hollow support member;
An annular wall extending upward from the base member;
With
The annular wall has an upper edge formed to support the bottom surface of the substrate holder so that gas within the annular wall and between the base member and the bottom surface of the substrate holder can be obtained. , Substantially preventing flow between an upper edge of the annular wall and a bottom surface of the substrate holder, the upper edge defining an upper opening of the hollow support member, the upper opening being A hollow support member defining an area of at least 70% of the size of the substrate. A substrate processing method comprising:
Providing a substrate holder including a generally flat central portion and a plurality of spacers, the central portion having an upper surface, a lower surface, and a plurality of passages extending from the upper surface to the lower surface, wherein the spacer includes the center; An upper support surface extending upward from the central portion and raised above the upper surface of the central portion, and the upper support surface of the spacer has a gap region between the upper surface of the central portion and the bottom surface of the substrate A step formed to provide support to the peripheral edge of the substrate;
Placing the substrate on the substrate holder such that the upper support surface of the spacer supports the peripheral edge of the substrate;
Directing an upward flow of gas directly into a lower end of one or more passages selected from the plurality of passages such that gas flows into the gap region;
Leaving the open lower end of the remaining one or more passages of the substrate holder; and
A substrate processing method. Further comprising flowing a reaction gas substantially horizontally above the substrate;
Flowing the gas upward includes flowing an inert gas directly into the lower end of the one or more selected passages simultaneously with the reaction gas flowing over the substrate. 37. A method according to claim 36. Providing one or more tubular arms;
Disposing an upper end portion of each arm directly below one of the plurality of selected passages;
Directing the gas upward into each tubular arm;
37. The method of claim 36, further comprising: Providing a hollow support member comprising a base member and a tubular structure extending upward from the base member;
Disposing the hollow support member under the substrate holder;
Further including
37. The annular structure according to claim 36, wherein the annular structure has an upper edge, and the upper edge is formed to restrict fluid flow across an interface between the upper edge and a lower surface of the substrate holder. The method described.   The annular structure such that at least one of the plurality of passages in the central portion has a bottom opening arranged to guide a downwardly flowing gas flow into a region outside the hollow support member. 40. The method of claim 39, further comprising the step of placing.   40. The method of claim 39, wherein positioning the hollow support member comprises engaging a lower surface of a central portion of the substrate holder with the upper edge.   37. The method of claim 36, further comprising directing a second flow of gas generally below and parallel to the lower surface of the central portion of the substrate holder.   The spacer includes an annular ring composed of a plurality of spaced blades, the blades being generally parallel to each other and angled with respect to the radial direction of the substrate. 40. The method of claim 36, wherein the method further comprises rotating the substrate holder about a central vertical axis.   44. The method of claim 43, wherein the step of rotating the substrate holder comprises rotating the substrate holder in a direction in which the blades impede inward flow of gas between the blades. A method of processing a substrate, comprising:
Providing a substrate holder including a generally flat central portion and a plurality of spacers, the central portion having an upper surface, a lower surface, and a plurality of open passages extending from the upper surface to the lower surface, An upper support surface extending upward from the central portion and raised above the upper surface of the central portion, the upper support surface of the spacer being a gap between the upper surface of the central portion and the bottom surface of the substrate A step formed so as to support the periphery of the substrate such that the region exists;
Placing the substrate on the substrate holder such that the upper support surface of the spacer supports the peripheral edge of the substrate;
Providing a hollow support member having a base and an annular wall extending upward from the base, the annular wall having an upper edge formed to engage the bottom surface of the substrate holder;
Engaging the annular wall with a bottom surface of the substrate holder, wherein the engagement is such that some of the plurality of passages guide gas flowing downward into the hollow support member. A lower end portion arranged, and at least one of the plurality of passages has a lower end portion arranged to guide a gas flowing out downward into a region outside the hollow support member. An engagement step performed on
Directing a gas flow directly to the inlet of the hollow support member;
Including methods. Directing a process gas above the top surface of the substrate;
Providing a gas source adapted to direct gas into the inlet of the hollow support member;
Preventing the pressure of the gas from the gas source from exceeding a height such that the gas from the gas source lifts the substrate from the substrate holder;
Setting the pressure of the gas from the gas source to a height such that dopant atoms diffusing outwardly from the bottom surface of the wafer are substantially swept away from the gap region;
46. The method of claim 45, further comprising:   The step of setting the pressure of the gas sets the pressure to such a height that dopant atoms that diffuse out from the bottom surface of the wafer are substantially swept away from the gap region through the plurality of passages of the substrate holder. 47. The method of claim 46, comprising the step of:   The step of setting the pressure of the gas includes the step of allowing the dopant atoms that diffuse out from the bottom surface of the wafer to pass through the opening having no thickness between the edge of the substrate and the annular shoulder of the substrate holder. 47. The method of claim 46, comprising setting the pressure to a height such that it is substantially swept away from the area.   The step of setting the pressure of the gas includes the step of allowing dopant atoms diffusing outwardly from the bottom surface of the wafer to pass through the plurality of passages of the substrate holder and between the edge of the substrate and the annular shoulder of the substrate holder. 47. The method of claim 46, further comprising the step of setting the pressure to a height such that the pressure is substantially swept away from the gap region through the opening. Directing a process gas above the top surface of the substrate;
Providing a gas source adapted to direct gas into the inlet of the hollow support member;
Setting the pressure of the gas from the gas source to a height that does not exceed a height at which the substrate will lift from the substrate holder;
In order to suppress the deposition of processing gas on the bottom surface of the wafer, the gap area is set such that the pressure of the gas from the gas source is high between the edge of the substrate and the annular shoulder of the substrate holder. A step of setting the height to flow gas inside,
46. The method of claim 45, comprising:

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